Electrical heating unit.



F. KUHN & J. A. HAND.

ELECTRICAL HEATING UNIT.

APPLICATION FILED FEB. 21. 1918.

Patented Oct. 22-, 1918.

STATES PATENT OFFICE.

rmx xurm am) JAY A. mm), or nnraorr, mcmean, assreuons mo sunarc'in ELECTRICAL HEATER COMPANY, OF DETROIT, MICHIGAN, A- CORPORATION 01" IICHIGAN.

underwear. HEATING UNIT.

Patented Oct. 22, 1918.

Application filed February 21, 1918. Serial No. 218,408.-

To all whom it may concern:

Be it known that we, FRANK KUHN and JAY A. HANI), both citizens of the United States of America, and both residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Electrical Heating Units, of which the following is a specification, reference being had therein to the accom anying drawings.

Tiie invention relates to electrical heating units of the exposed resistor type and has for its object simplicity in construction, thorough protection or guarding of the resistor, mechanical strength and ease in assembly. The invention consists in the novel construction as hereinafter set forth. i

In the drawings:

Figure l is a perspective view of the unit;

Fig. 2 is a sectional plan view of a portion, of the unit;

Fig. 3 is a cross-section on line 3- -3 of Fig. 2; I

Fig. 4 is a cross-section on line 44 of Fig. 2;

Fig. 5 is a perspective view' showing the manner of assembling the elements of the unit. A are insulator strips, preferably formed of mica and which are centrally apertured at intervals with metallic eyelets B. C and C are metallic strips of U-shaped crosssection, which embrace the opposite edges of ing ooiiperating notches F therein. The 4 construction is such that by arranging a series of the strips A in parallel relation they may be spaced and held in this relation by engagement with the cross strips E. The resistor G, referably in the form of a coil, is threaded through the eyelets back and forth between the strips so as to be dis tributed'ihs uniforml as possible over the area ofthe unit. he threading may be performed before the cross-bars E on one side of the unit are placed in position, but

when'completed said cross-bars E will constitute a grid protecting the resistor from injury or short circuiting.

The unit is preferably inclosed in an outer peripheral band H formed of a sheet-metal strip, and the ends of the strips C and E may be engaged with notches in this band and clenched, as indicated at I. At one point the band H is cut away at J for the passage thereth'rough of the terminal conductors. These conductors, K, are preferably mounted on an insulator block L, which in turn is mounted. on a metal bracket member M having a seglmental portion M fitting against the band The inner ends of the terminal conductors K pass through apertures M in the portion M and are held from contact therewith by an insulator strip N, preferably of mica, which may be clamped between the member M and the band H. Thus the terminals will be mechanically fixed in relation to the unit and electrically insulated from the frame thereof. The resistor is suitably connected to the portions of the terminals K projecting inward through the apertures M by means of clamping screws K which are readily accessible through the openings between the bars of the grid.

With the construction described the internotched and crossing metallic strips will form a strong mechanical structure without shielding to any great extent the radiation from the resistor, the mica strips will form thorough electrical insulation and the metallic eyelets therein will protect the edges around the apertures for the resistor both mechanically and from overheating. The unit is therefore as strong and substantially well protected as an armored resistor, and on account of the exposure of the resistor is more efficient as a radiant element.

What we claim as our invention is;

1. An electrical heating unit, comprising a peripheral band, a series of strips extending across the area inclosed by saidband, each comprising a mica strip having a series of eyelets therein and binding strips embracing the opposite edges of said mica strips and notched at intervals, a resistor threaded through said eyelets back and forth between said strips, and cross-strips having cooperating notches therein for engagement with the notched edge of said binding strips and having their opposite ends extend through said band'and clenched thereover.

2. An electrical heating unit, comprising .a peripheral band having a portion cut nected to said resistor and passin through periphery and secured thereto and .havm% apertures therethrough for the passa e 0 .said terminal conductors, and an insu ator strip between said band and member, said insulator -strip maintaini said terminal conductors out of contact wit said band and member.

In testimony whereof we affix our signatures. v

FRANK KUHN. JAY A. HAND. 

